When an app is uninstalled, is the data in its SharedPreferences database deleted?
If not, without a device being rooted, is there any way to clear that data? (Or at least view it?)
asked Jun 12, 2019 at 20:18
-
SharedPreferences is located in the data directory of the app which gets deleted during uninstallation. Do you have a case where it was not deleted by the system?– Firelord ♦Commented Jun 12, 2019 at 20:36
-
@Firelord I was reading up on Stack Overflow on how to make an app with a "trial period". One of the answers recommended writing data to SharedPreferences, because they claimed it can remain when an app is uninstalled. That doesn't match what I remembered, so I thought it best to ask.– Amazon Dies In DarknessCommented Jun 12, 2019 at 20:41
-
SharedPreferences are backed by Google if the app participates in the backup. It would be best if you clarify whether "they" assumed your app would be backed up.– Firelord ♦Commented Jun 13, 2019 at 5:58
-
@Firelord I don't back up anything to Google (well, not intentionally), so I'm looking up what you're referring to. I see a "Back up my data" option deep within Android Settings... is that it?– Amazon Dies In DarknessCommented Jun 13, 2019 at 6:34
-
1If auto backup is the issue, then you can clear the app data after reinstalling to delete all the shared preferences.– Andrew T. ♦Commented Jun 14, 2019 at 10:03
|
Show 3 more comments
2 Answers
SharedPreferences are actually saved in a file in the app private directory:
/data/data/package_name/shared_prefs/somefilename.xml
When an app is installed this directory and file are automatically created. When an app is uninstalled this directory is deleted along with its parent /data/data/package_name UNLESS the app is uninstalled in order to update it.
From command line this is done using the flag -k or -r that is
adb uninstall -k package_name - Keep the data and cache directories around after removal
adb install -r package_name - Replace existing application (effectively reinstall an existing app, keeping its data)
SharedPreferences database always deleted when app is uninstalled. But when in the AndroidManifest.xml allowBackup is set true then data is not cleared even if application is uninstalled and re-installed.
android:allowBackup="true"
So, always keep allowBackup to false when you don't want the data to be stored.
-
Thank you. What is the best way to keep allowBackup as false? Commented Jun 14, 2019 at 6:35
-
3@user298642 The allowBackup flag usually only affects the
adb backup. Do you have a source that backs your answer?– RobertCommented Jun 14, 2019 at 19:57 -
@Robert I found these reference developer.android.com/identity/data/autobackup developer.android.com/identity/data/…– situeeCommented Aug 29 at 2:01